• Steel and Composite Structures
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• 제44권6호
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• pp.845-865
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• 2022

In this study, the performance of shear deficient reinforced concrete (RC) beams with rectangular cross-sections, which were externally bonded reinforced (EBR) with high strength CFRP and GFRP strips composite along shear spans, has been experimentally and analytically investigated under vertical load. In the study, the minimum CFRP and GFRP strips width over spacing were considered. The shear beam with turned end to a bending beam was investigated by applying different composite strips. Therefore various arising in each of strength, ductility, rigidity, and energy dissipation capacity were obtained. A total of 12 small-scaled experimental programs have been performed. Beam dimensions have been taken as 100×150×1000 mm. Four beams have been tested as unstrengthened samples. This paper focuses on the effect of minimum CFRP and GFRP strip width on behaviours of RC beams shear-strengthened with full-wrapping, U-wrapping, and U-wrapping+longitudinal bonding strips. Strengthened beams showed significant increments for flexural ductility, energy dissipation, and inelastic performance. The full wrapping strips applied against shear failure have increased the load-carrying capacity of samples 53%-63% interval rate. Although full wrapping is the best strengthening choice, the U-wrapping and U-wrapping+longitudinal strips of both CFRP and GFRP bonding increased the shear capacity by 53%~75% compared to the S2 sample. In terms of ductility, the best result has been obtained by the type of strengthening where the S5 beam was completely GFRP wrapped. The experimental results were also compared with the analytically given by ACI440.2R-17, TBEC-2019 and FIB-2001. Especially in U-wrapped beams, the estimation of FIB was determined to be 81%. The estimates of the other codes are far from meeting the experimental results; therefore, essential improvements should be applied to the codes, especially regarding CFRP and GFRP deformation and approaches for longitudinal strip connections. According to the test results, it is suggested that GFRP, which is at least as effective but cheaper than CFRP, may be preferred for strengthening applications.

• ETRI Journal
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• 제39권3호
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• pp.428-436
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• 2017

State-of-the-art processors require increasingly complicated memory services for high performance and low power consumption. In particular, they request transfers within a burst in a wrap-around order to minimize the miss penalty of a cache. However, synchronous dynamic random access memories (SDRAMs) do not always generate transfers in the wrap-round order required by the processors. Thus, a memory subsystem rearranges the SDRAM transfers in the wrap-around order, but the rearrangement process may increase memory latency and waste the bandwidth of on-chip interconnects. In this paper, we present a memory subsystem that is effective for the wrapping bursts of a cache. The proposed memory subsystem makes SDRAMs generate transfers in an intermediate order, where the transfers are rearranged in the wrap-around order with minimal penalties. Then, the transfers are delivered with priority, depending on the program locality in space. Experimental results showed that the proposed memory subsystem minimizes the memory performance loss resulting from wrapping bursts and, thus, improves program execution time.

• 한국정보과학회논문지:소프트웨어및응용
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• 제36권12호
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• pp.1024-1027
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• 2009

본 논문에서는 혼합형 데이터에 대한 특징 선별 기법의 효율성을 비교하기 위해 특징 필터링과 특징 래핑을 통한 특징 선별 후, 클래스 분류 성능을 측정하였다. 혼합형 데이터는 숫자형 특징과 범주형 특징이 함께 혼합되어 있으므로, 숫자형 특징을 범주형 특징으로 이산화를 하여 단일형 데이터로 변환한 뒤 특징 선별 기법 등을 적용할 수 있다. 본 연구에서는 혼합형 데이터를 전처리하여 단일형 데이터로 변환하고, 널리 활용되는 특징 필터링 기법과 특징 래핑 기법을 통해 클래스 분류 성능을 높일 수 있는 특징 집합을 선별하였다. 선별된 특징 집합을 통한 클래스 분류 성능을 비교한 결과, 특징 필터링에 비해 특징 래핑을 통해 선별한 특징 집합을 활용하여 클래스 분류를 하였을 때 분류 정확도가 높은 것을 확인할 수 있었다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제13권7호
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• pp.499-507
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• 2007

프로그래밍 언어에서 변수를 사용하여 메모리의 특정 영역을 접근하는 것처럼, 텍스트 파일의 특정 영역도 문자열 이름을 가지는 변수로 표현하여 해당 영역의 값을 읽고 수정할 수 있는 텍스트 파일 인터페이스를 지원할 수 있다. 이것을 CAE, CAD, CAO 통합 자동화 시스템 분야에서는 파일 랩핑 (File Wrapping) 이라 한다. 파일 랩핑은 CAE, CAD, CAO 통합 자동화의 핵심 기술 중 하나이면서, 파일의 크기와 영역의 개수 및 분포에 따라서 통합 자동화 시스템의 실행 속도에 큰 영향을 미친다. 본 논문에서는 파일 랩핑의 핵심 기능을 일반화한 텍스트 파일 영역 관리 모델을 정의하고, 이를 그리드 서비스로 구현한 프로토타입의 구조를 설명한다. 그리고 구현된 프로토타입의 실행 결과 분석을 통하여, 제안된 모델과 텍스트 파일 영역 관리 서비스의 효용성을 검증한다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.339-342
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• 2003

The bridge columns with lap-splice reinforcements in earthquake suffered a brittle bond-slip failure due to deterioration of the lap-spliced longitudinal reinforcements without developing its flexural capacity or ductility. In this case, such a brittle failure can be controlled by the seismic retrofit using FRP wrapping. The retrofitted columns using FRP wrapping showed significant improvement in seismic performance due to FRP's confinement effect. This paper presents the circumferential confinement effect of existing circular bridge pier strengthened with FRP wrapping for poor lap-splice details. The effects on the confinement of FRP wrapping, such as gap lengths between footing and FRP, fiber orientations, and thicknesses of FRP, were investigated by quasi-static experiments.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.280-287
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• 2003

The bridge columns with lap-splice reinforcements in earthquake suffered a brittle bond-slip failure due to the deterioration of lap-spliced longitudinal reinforcement without developing its flexural capacity or ductility. In this case, such a brittle failure can be controlled by the seismic retrofit using FRP wrapping. The retrofitted columns using FRP laminated circular tube showed significant improvement in seismic performance due to FRP's confinement effect. This paper presents the circumferential confinement effect of existing circular bridge pier strengthened with FRP wrapping for poor lap-splice details. The effects on the confinement of FRP wrapping, such as gap lengths between footing and FRP, fiber orientations, and thicknesses of FRP, were investigated by Quasi-static experiments.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.250-253
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• 2006

This paper presents experimental studies on investigating the seismic retrofit performance of reinforced concrete circular columns with poor lap-splice details using GFRP wrapping. Four 1/2 scale-down model columns have been tested. The as-built column is expected to suffer brittle failure due to the bond failure of lap-spliced longitudinal reinforcement. The retrofitted columns using GFRP wrapping showed significant improvement of seismic performance.

• 한국축산시설환경학회지
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• 제20권3호
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• pp.105-116
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• 2014

In this study, we developed a fermented TMR producing system which could a continuous operation of baling and wrapping the mixed TMR. The baling part has fixed chamber of dia. 900 mm and width 900 mm. And the the turn-table type wrapping part is very compact compared to conventional one in market. The test result were: The absorbed power of the prototype in working was 9.0~15.7 kW. The combined baling and wrapping performance was over 20 bales/hr. The leakage in the process was around 1.9 kg for making a 350 kg TMR bale. The diameter of wrapped TMR bale was 900~950 mm, and its weight was 350 kg in average. Therefore the density was $718kg/m^3$, and it was very high density to the inputted TMR. The pH of the fermented TMR was 5.0~5.6 which was similar to the fermented haylage, also the TMR had no butyric acid's odor.

• 생물환경조절학회지
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• 제8권4호
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• pp.250-256
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• 1999

본 연구는 랩을 이용하여 장방형 과채류의 자동포장기를 개발하기 위하여 수행되였다. 과채류의 포장은 과채류의 수분유출을 방지하고, 공기공급을 가능하게 하여 과채류의 신선도를 유지 할 수 있을 뿐만 아니라, 과채류를 직접 포장함으로써 운반도중 조기 부패하거나, 표피의 손상을 억제할 수 있다. 또한 포장에 의한 농촌의 일손 부족문제를 해결하고 소포장 단위의 신선한 과채류를 원하는 소비자의 구매욕구를 충족시킬 수 있도록 있는 자동포장기를 개발하였다. 랩을 이용한 장방형과 채류를 1개 이상 자동으로 포장할 수 있는 시스템을 개발하였다. 가지의 포장율은 상품, 중품 모두 포장율이 100%로 매우 우수하게 나타났는데, 이는 포장을 위한 회전단면적이 비교적 균일하고 또한 가지 표면의 물리적 특성 때문으로 판단된다. 오이의 포장율은 매우 우수하였으나, 중품은 상품에 비하여 떨어지는 것으로 조사되었는데, 이는 굽은 정도가 포장율에 영향을 미치기 때문으로 생각된다. 애호박의 포장율은 개수가 증가할수록 떨어지는 것으로 나타났는데, 이는 단면적이 컸기 때문으로 판단된다. 장방형 과채류의 포장개수별 포장효율은 회전단면적의 차이에 따라 효율이 변하는 것을 알 수 있었다.

• Journal of Biosystems Engineering
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• 제27권3호
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• pp.195-202
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• 2002

In order to make a winter cereal wrap silage, a tractor attached round bale wrapper was developed locally. Its specific structure and various functions were reported in the last submitted paper. In this study a control system of bale wrapper combining with the actuators of various processes was developed to make round bale wrapper compatible in the field. Also. its performance was tested by making the rye round bale. The results can be summarized as fellow. 1. The field capacity of round bale wrapping was investigated around 0.5 ha/hr, and the operating time of bale wrapper was about 3 min for each 500kg round bale 2. Plastic film which has maximum elongation rate of 796% was stretched to 150∼170% of original length and was lessened to 80∼90% of original width. 3. In the quality test of bale produced by developed bale wrapper, there was no significant changes of moisture contents if it was wrapped more than 4 layers of 25 ㎛-plastic film. 4. Also. temperature of the wrapped bale was about 33$\^{C}$ in the beginning of fermentation and was stabled to 26∼29$\^{C}$ during one month or more storage. Therefore, wrapping performance of the developed bale wrapper was properly.